Typical products 19 which are treated in the fryer 10 include, for example, onion rings as well as other vegetables; meats such as chicken and beef as well as fish. These food products as choice can be first dipped in a viscous batter and then covered with a layer of bread crumbs or similar coating which adheres to the batter, thus increasing the weight of the product. Unless handled carefully in the cooking operation, a portion of the breading or other coating will not adhere to the product and will fall into the cooking oil which is undersirable as discussed above. Desribed below are steps which materially reduce the amount of brad and batter material stripped from the product through the cooking operation when such products are so breaded.
A number of successfully marketed food products, chicken, beef, fish, filled dough, vegetables, etc. sometimes are prepared by coating or battering the product and covering the coating with bread crumbs or the like and frying thereafter. During the frying step in which the product is either partially or fully cooked, it is highly desirable that as much of the breading or other coating be retained on the product and that a very minimum of the coating slough off into the cooking oil. When particles of the coating break away from the product, this results in a lower production yield and the fines sloughed off contaminate the frying oil. These breading and product fines must be removed from the frying medium on a regular basis to avoid degrading the cooking oil to a point where it must be supplemented by a higher quality oil or else removed for recycling. This event places a high economic burden on control of the cooking oil as well as control on the battered and breaded product. Maintaining a balance between product yield and oil quality has been a challenge which faced food processors over a long period of time. This is true as well of the non breaded and battered products that comprises the bulk of the market.
Prior art equipment and techniques were developed in attempts to minimize the removal of breading or other coatings from the underlying food product. In the conventional hot oil cooking fryer substantial turbulence or xe2x80x9cboilxe2x80x9d is generated when the relatively cold uncooked food product is dropped into the hot cooking oil. This turbulence contributed to removal of portions of coatings and continued to a lesser degree as the product is conveyed through and cooked in the hot oil bath. To overcome this undesirable effect food processors turned to cooking the products in batch cookers where the relative motion between the product and the cooking oil would be quite low, although the initial turbulence or xe2x80x9cboilxe2x80x9d was always present. Other procedures involved cooking in ovens after applying an oil spray coating as a preparatory step to the oven cooking. Gentle handling of the coated product while cooking was a desired goal but rarely achieved to complete satisfaction for high product yields with high production output.
It is highly desirable to minimize the relative motion between the bread and battered product and the cooking medium, whether the cooking medium is cooking oil or a process cooking vapor. This is evident because a rapidly moving cooking medium is more than likely the cause of portions of the bread coating to be removed from the product which thereby reduces the yield on the one hand and produces contamination of the cooking medium on the other.
Where the choice is made to cook a breaded and batter product in cooking oil there are substantial advantages in using the minimum practical amount or volume of cooking oil. However where the product fryer has a large bath of cooking oil, the large air-oil surface and the consequent exposure of the cooking oil to air causes the oil to degrade. Replacement of the complete oil bath or make-up oil must be supplied to maintain or uphold the desired cooking oil quality. Shoed the oil degrade significantly, there will be caused an xe2x80x9coff tastexe2x80x9d to be imparted to the product. This must be guarded against to avoid product rejection for quality control reasons as well as to postpone the costly replacement of the degraded oil. In the prior art use of a reduced volume of cooking oil has been thought to be impractical where high product output is the goal.
In summary, the invention is comprised of an improved fryer for treating a food product with hot cooking oil gently dispensed from above onto the food product. The food products are normally mechanically delicate. The fryer is comprised of a housing defining an enclosed cooking zone and having exhaust vents for withdrawing cooking vapors and odors therefrom. A main endless conveyor with variable speed drive is provided for transporting the food product through the cooking zone and includes a conveyor belt through which cooking oil may flow freely. A submerger conveyor may be provided arranged superimposed on the main conveyor, for submerging products which tend to float. A plurality of cooking oil inlet distribution stations are spaced longitudinally apart along said main conveyor and are arranged above the product carrying conveyor belt a distance sufficient to permit the product to pass thereunder. The cooking oil distribution stations extend substantially the full-width of the conveyor belt for treating the food products as they are carried through the fryer housing. Each cooking oil inlet distribution station includes a cooking oil reservoir of relatively small surface area exposed to the steam/air atmosphere and equipped with at least one overflow weir permitting the cooking oil to flow there over in an unbroken vertical curtain downwardly onto and over such food product carried upon the conveyor belt. A cooking oil feed conduit serves to supply each cooking oil distribution station, the feed conduit having multiple discharge openings disposed in the reservoir below the atmosphere-oil surface level so that as oil flows over as the weir in a curtain enrobing the product, the reservoir is resupplied with oil beneath the oil liquid level.
Another feature permits cooking a product while it is fully submerged in cooking oil in which application the distribution station provides for the gentle return to the fryer of the externally heated cooking oil while maintaining a substantially uniform oil temperature along the length of the fryer.
In another aspect the invention comprises an improved process for treating a food product such as one which typically carries a pre-cook coating that is fragile and easily dislodged if safeguards are not taken, comprising the steps of providing a fryer having an endless conveyor including a conveyor belt through which oil can flow freely, and providing a volume of cooking oil in the fryer, and maintaining the oil level such that the food products carried on the conveyor are not completely submerged in the cooking oil, placing such food products with the fragile coating on the conveyor at a loading station for treatment in the fryer, then moving the food products towards an unloading station while dispensing from above the conveyor and onto the product at least one smooth, flowing curtain of hot oil, and controlling the oil flow so that it flows downwardly, continuously in a curtain of oil covering coating and enveloping the food product on the conveyor sometimes referred to as an xe2x80x9cenrobingxe2x80x9d processxe2x80x94and then removing the treated food product from the fryer at the unloadig station.
A general object of the invention is to provide an improved breaded products fryer for continuously processing a breaded and battered product that is fragile by applying cooking oil to the product from dispensing stations arranged above the product such that the oil will free fall in a curtain onto the product and cook the product in an enrobing action.
Another object of the invention is to provide an improved breaded products fryer of the type described wherein the volume of cooking oil utilized is substantially less than that in prior art fryers of similar capacity and where in the tendency of oil to degraders correspondingly less than in prior art fryers.
Still another object of the invention is to provide an improved breaded products fryer wherein a continuous product conveyor is arranged in a fryer pan such that the return run of the conveyor continuously sweeps the conveyor bottom moving loose bits of product, crumbs and other fines to a fines removal facility or oil outlet sump on the fryer which may be positioned proximate to the product inlet end of the fryer.
Yet another object of the invention is to provide a fryer of the type described wherein the product conveyor belt is arranged with a return run outside of the fryer pan and with an oil return sump positioned proximate to the product discharge end of the fryer.
Another object of the invention is to provide an improved breaded products fryer of the type described which is equipped with a product hold-down conveyor super-imposed upon the principal product conveyor.
Still another object of the invention is to provide a new and improved continuous process for treating products including a breaded and battered food product by gently flowing cooking oil over the product as the product is conveyed through the frying process, whether the product is fully or partially submerged or completely exposed and not submerged in the cooking oil.
Yet another object is to provide an improved process of cooking a breaded and battered food product by supplying a plurality of downwardly flowing curtains of cooking oil flowing upon the food product enrobing it as it moves through the cooking process.
In accordance with the foregoing object, it is a further object to provide for a multi-zone frying process wherein cooking oil is applied to the food products at a plurality of locations along the cooking path at preselected oil temperatures, such temperatures being either uniform or following preselected cooking oil temperature curves to more advantageously cook a wide variety of food products.
Still another object is to provide a process as described above wherein cooking oil turbulence is materially reduced at the moment of hot cooking oil contact with the cold uncooked product thereby reducing the forces tending to remove coatings from the food product and producing a highly improved cooked product yield and a superior product in which the surface coating is not partially or fully lost, which loss would expose the xe2x80x9cmeatxe2x80x9d and render the finished product inferior in the eyes of the consumer.
These and other objects of the invention and advantages from its use will become more apparent from the detailed description which follows, taken in connection with the accompanying drawings.